This DHT11 Digital Relative Humidity & Temperature Sensor Module is pre-calibrated with resistive sense technology coupled with NTC thermistor, for the precise reading of the relative Humidity and surrounding temperature DHT 11 break-out board is a very popular, low-cost sensor from Aosong, the breakout provides easy installation of the DHT11 sensor module.

The board is also equipped with high- performance 8-Bit microcontroller which is connected to the DHT11 sensor module. The output of the DHT11 is in the form of a digital signal on a single data pin. The sensing update frequency is to be measured at every 2sec (0.5Hz).

The complete arrangement makes the device an ideal sensing setup to be hooked up directly to any kind of microcontroller boards like Arduino’s. The board is extra featured with onboard LED, a bypass capacitor between Vcc and Gnd and a pull-up resistor across the data line and Vcc.

The DHT-11 Digital Temperature And Humidity Sensor is a basic, ultra low-cost digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air and spits out a digital signal on the data pin (no analog input pins needed).

Its fairly simple to use, but requires careful timing to grab data. The only real downside of this sensor is you can only get new data from it once every 2 seconds, so in your code please use sensor reading interval at 2 seconds or more. Compared to the DHT22, this sensor is less precise, less accurate and works in a smaller range of temperature/humidity.

But despite its disadvantages over DHT22, it is smaller and less expensive sensor for temperature and humidity measurement.